Locomotive-boiler firebox



Jan. 29, 1929.

c. M. ROGERS- LOCQMOTIVE BOILIER FIREBOX Filed'Mai'ch 8. 1926 2 Sheets-Sheet 1 --ZZM /Zf02" Jan. 2 9, 1929.

C. M. ROGERS LOCOMOTIVE BOILER FIREBOX I 1 Filed March 8.1926 2 Sheets-Sheet 2 Patented Jan. 29, 1929.

UNITED STATES PATENT OFFICE- CECIL M. ROGERS, OF CHICAGO, ILLINOIS, ASSIG'NOR TOLOCOMOTIVE FIREBOX. 00., OF CHICAGO, ILLINOIS,'A CORPORATION OF DELAWARE.

LOCOMOTIVE-BOILER FIREBOX.

Application filed March 8, 1926. Serial No. 93,350.

This invention relates to improvements in locomotive boiler fireboxes and especially to thoseequipped with the well known Nicholson thermic siphons and the invention consists in the matters hereinafter described and more particularly pointed out in the appended claim. I v

The Nicholson thermic siphon isone form of a water circulating and steaming member installed in the firebox of a locomotive boiler, for increasing the efficiency of the boiler and it usually consists of an inverted substantially triangular flat tubular body having a tubular neck, the neck being secured in and opening through the frontsheet and the body being usually secured in the opening through the crown sheet so as. to afford a free passage of water from the throat to the boiler space above the crown sheet. I In the operation of the locomotive the siphon is subjected to an intense heat whichcauses an expansion of the I siphon and when the fire is drawn and the.

siphon cools down, it of course contracts. Means have been provided to compensate for.

7 the expansion and contractionof the siphon and the best means yet discovered consists, in an annularlycorrugated diaphragm like portion in the inner throat sheet with the neck fixed concentrically therein. Other means such as slip joints between the throat sheet and siphon neck have been employed, but as they have not proven asefficient as the diaphragm connection, they have not been received with favor in the railroad industry.

.I have found through experiments and. demonstration that in fthe'annularly corrugated diaphragmwith the'neck disposed concentrically therein, a peculiar cramping condition arises in the diaphragm which prevents its most eflicient operation for its intended purpose. I I

The primary object of the present invention is to improve the connection between the siphon neck-and diaphragm whereby the diaphragm may operate to the maximum efficiency for its intended purpose.

.A further object of the inventionis to position the neck oif center with respect to the diaphragm and closer to that portion thereof wherein the diaphragm tends to ful cr'um in its breathingor pulsating like movement,'which movement is not concentric with the corrugations of the diaphragm as has heretofore assumed to be the case.

The above mentioned objects of the invention, together with others, as well as the many advantages thereof will more fully appear as I proceed with my specification.

In the drawings:. I I r Fig. 1 is a vertical longitudinal section through the firebox end of a locomotive boiler embodying one form of my invention' Fig. 2 is a detail view on an enlarged scale ofparts shown in Fig. 1 and whichwill-be more fully referred to later.

Fig. 3 is a transverse vertical detail sectional view as taken onthe line 3-3 of Fig. 2.

Fig. 4 is a horizontal detail sectional view as taken on the line 4 -4 of Fig. 2.

Fig. 5 is a detail view of parts shown in Fig. 2 but on an enlarged scale to illustrate the breathing action of the diaphragm'in accordance with my invention.

Fig. 6 is a detail view similar to Fig: and I shows a modified form of my invention. Referring now in detail to that embodiment of the invention illustrated in Figs. 1 to 5 inclusive of the accompanying drawings, the locomotive boiler fire box shown therein comprises a fire chamber which ex-. tends from the back sheet 1 to the flue sheet 2 and from one to the other of the side sheets 3 with a grate or bottom indicated by the dotted line 4 in Fig. 1.- Said grate, as shown herein, extends from the'ba'cksheet 1 to an inner throat sheet 5 which is preferably integral with the flue sheet. The top of the fire box is formed by a crown sheet 6 which extends from the back sheet 1 to the flue sheet 2. a

In the rear sheet 1 is provided the usual fuel door opening 7 andto the front or flue sheetare connectedthe usual flues 8'through which the products of combustion .are drawn of which are closed at their bottom ends by themud ring 14. The inner sheets defining the firebox and the outer or wrapper sheets are joined or stayed together by the usual stay bolts 15.

l/Vithin the fire box is located one or more substantially triangular hollow elements 16 which conduct water from the front water leg or throat 12 of the boiler to the space 17 above the crown sheet 6. Only one of such elements which are known as the Nicholson thermic siphons are shown herein, the number of such siphons employed of course be ing dependent upon the size of the fire box.

The water circulating element or siphon shown. herein embodies an upwardly and rearwardly inclined tubular bottom or neck portion 18 and a progressively upwardly enlarging and substantially triangular hollow body portion 19. The lower part of said bottom portion or neck 18 constitutes the inlet or intake end ofthe element which is in open and unobstructed communication with the water space below the fines 8. As shown herein said neck leads from the top end part of the front water leg 12 of the boiler. The body 19 of the element has flat sides 2020 suitably stayed together, and the top end thereof is formed to provide a flange 21 which is fixed to portions of the crown sheet and which defines an elongated opening 6 therein. The body of the siphon is open at its top so as to be in communication with the water space 17 above the crown sheet and one side or end of said body is formed with a bulged or tubular part 22 which in effect is a continuation of the neck 18. Thus water may flow and rise freely from the bottom of the boiler into the watercirculating element or elements, in which it is heated and thence rises rapidly into the space above the crown sheet. Much of the water is converted into steam within this elementwhich in turn hastens the upward flow of water not only through the body of the element but also through the neck thereof and which water passes out through the open top end of the element into the water space above the crown sheet. Thus a vigorous circulation of water through the boiler is secured together with a constant flooding and washing of the crown sheet.

The throat sheet 5 or more particularly speaking, that portion thereof immediately surrounding the neck 18 of the element is so made as to come and go with the element as it expands or contracts due to temperature changes in the fire box. Heretofore that portion of the throat sheet surrounding said neck has been annularly corrugated, concentrically with respect to said neck and this operated in a mannersubstantially as and for its intended purpose. However such a construction has its disadvantages and it is these disadvantages I have overcome in the construction illustrated herein and now to be described. I have found that in actual use the movement of the neck 18 under expansion and contraction of the element is not all in a plane parallel with the axis of said neck as heretofore assumed so that by disposing the annular corrugation concentrically with the neck a kind of a cramping action takes place which hindered the free movement of said neck. Such movement appears to be a movement whch fulcrums or centers about a peripheral portion of the neck and this portion is always at the top side of the neck when a vertical plane is considered. To meet such a condition I provide in the inner throat sheet adiaphragm portion 23 defined by an annular corrugation 24 and in said portion but eccentric with respect to said corrugation is a short sleeve 25 which projects towardthe fire box proper and into which the end of the neck 18 extends and is welded as indicated at 26.

In forming the annular corrugation, the top part 24 thereof is not only of a radial width less than the bottom part 24" as best shown in Fig. 2 but said top part is also of a depth less than said bottom part. Thus in the movement of siphon neck which tends to fulcrum or pivot about the top part of inner throat sheet, adjacent the neck, the bottom part being radially wider and also deeper is more flexible and capable of more movement as is best shown by the dotted lines in Fig. 5. With such a construction as just described, it is apparent that those portions of the annular corrugation on both sides (as distinguished from the top and bottom) of the neck are of the same depth and radial width as best shown at 24 in Fig. 4.

Instead of making the diaphragm as an integral part of the throat sheet 5 it may be made of a separate piece of firebox plate material. Such a construction is shown in Fig. 6 wherein 23"= indicates the diaphragm, made from a circular plate. and which is welded within a correspondingly shaped opening 5* in the throat plate as indicated at 27 in said figure, the similar parts bearing the same reference numerals as before.

By forming the diaphragm and positioning the neck receiving sleeve therein, as before described, the movement of the siphon neck under contraction and expansion is free and unhindered by any cramping or binding and consequently, the metal of the diaphragm does not fatigue or break down as soon as heretofore. p

While in describing my invention, I have referred to certain details of mechanical construction as well as form and arrangement of the parts thereof, the same is intended as by way of illustration only and not by way of limitation except as may be set forth in the appended claim.

I claim as my invention:

A locomotive boiler firebox, in combination with a substantially rigid water circulating llll element disposed in said firebox and having ends Which open through the sheets thereof at different elevations, one of said sheets having an annularly corrugated flexible por- 5 tion with its flexing fulcrum disposed eccentrio with respect to corrugation thereof the groove of the corrugation increasing in Width and in depth from the top to the bottom on either side, and one end of said element be ing fixed in said corrugated portion adjacent 10 said fulcrum.

In testimony whereof, I have hereunto set my hand, this 26th day of February, 1926. CECIL M. ROGERS. 

